Two coffee brokers in the world’s largest producer of beans, Brazil, told Bllomberg News that coffee prices have tumbled since growers have begun selling beans.

Flavour Coffee and Cazarini Trading Co. told Bloomberg that many growers were holding onto beans to try to increase demand and boost prices, but that 132-pound (60 kilo) bags are now trading for less than $291, the lowest rate since last August. Prices are down for arabica and robusta beans.

It was “a dramatic and nervous week,” Thiago Cazarini, a broker at Varginha, Brazil-based Cazarini Trading Co., wrote in a report e-mailed to Bloomberg. “Prices dropped in the internal market, with futures coming much lower.”